Poly(L-Lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) is a water soluble copolymer consisting of a poly(L-Lysine) backbone and poly(ethylene glycol) side chains (Sawhney et al. Biomaterials 1992 13:863-870). The PLL chain, which carries multiple positive charges, spontaneously adsorbs onto negatively charged surfaces while PEG is a polynonion which serves as a non-binding domain. This adsorption is strong and occurs rapidly, and renders surfaces protein and cell resistant. Furthermore, PLL-g-PEG has been shown to improve the biocompatibility of materials. (Sawhney et al. Biomaterials 1992 13:863-870)
Various applications for the PLL-g-PEG graft co-polymer, block co-polymers, and dendrimers with similar binding characteristics have been described.